This invention relates to an improved method for beneficiating titanium-bearing material containing iron.
High grade titanium-bearing material containing low amounts of iron is becoming increasingly scarce and expensive. While low grade titanium-bearing material containing significant amounts of iron can be used in the chloride process for making titanium dioxide pigment or titanium metal, significant amounts of iron chloride byproduct are produced. Some byproduct iron chloride can be used as a flocculant to remove sediment in the treatment process to produce potable water. Because, however, the amount of iron chloride required for this use is limited, the production of significant amounts of iron chloride can be a waste disposal problem.
A number of different processes have been proposed to beneficiate titanium-bearing material containing iron. These processes, however, appear to be deficient in one or more aspects, including, (a) being expensive or not feasible on an industrial scale or (b) producing iron chloride which has the aforementioned disposal problems, and producing low-grade iron.
The following information is to disclose which may be of interest in the examination of this application:
U.S. Pat. No. 3,929,463 discloses a continuous method of effecting an endothermic metallurgical reduction reaction in the reactor space of a rotatable mechanical kiln which functions as a reaction vessel. During the reaction, the charged kiln is rotated at a speed which is lower than the speed at which the charge closest to the kiln ceases to move relative to the wall. The charge is thereby disintegrated and heated to effect the reaction. The reaction carried out can be the reduction of iron, copper, nickel or zinc oxides or sulfides. It is also disclosed that the process can be used to reduce the iron content in titaniferous magnetite and ilmenite in the form of magnetic power which then can be separated magnetically.
British patent 1,397,200 discloses a process for producing metallic iron from materials containing iron oxides and a nonferrous metal oxide. In the process, the oxide containing material is heated in a furnace in the presence of hydrogen chloride, a flux, and a solid carbonaceous material, to a temperature below that at which a slag is formed.
UK published patent application 2,000,755 states that particles containing a mixture of iron and titanium oxide can be heated in a nonoxidizing environment with an iron salt or a precursor thereof to segregate the iron from the titanium bearing component. The process may be applied to beneficiation of ilmenite by first reducing the iron component thereof to metallic iron. The segregated iron can then be separated from the titanium bearing component by physical or chemical means.
An article entitled "Kinetics of Reduction of Ilmenite with Graphite at 1000 to 1100 degrees C." by S. K. Gupta, V. Rajukumar, and P. Grieveson, appears in the December 1987 issue of Metallurgical Transactions and discloses an experimental process for reducing ilmenite with graphite. It is stated by the authors that the rate is increased significantly by the addition of ferric chloride, which promotes the nucleation of iron.
An article entitled "Reduction of Ilmenite with Carbon", by D. K. Gupta, V. Rajakumar, and P. Grieveson, appearing in the June, 1988 issue of Metallurgical Transactions, discloses an experimental process for the reduction of ilmenite ore with coal in the presence of ferric chloride. According to the authors, the ferric chloride promoted the nucleation of iron and increased the rate of reduction.